JP4295139B2 - Structure and connecting method of connecting part between transmission and drive shaft - Google Patents

Description

  The present invention relates to a connecting portion structure between a transmission and a drive shaft, and a connecting method of a transmission having the connecting portion structure and a drive shaft. In the present specification, the “transmission” is a broad meaning including all of a reduction gear, a speed increaser, and a variable transmission (a transmission in a narrow sense).

  Conventionally, for example, when one or both of a motor and a speed reducer are general-purpose products, a connection via an input member (input shaft) also serving as a coupling is generally performed in order to connect the two. For example, Patent Document 1 discloses a structure in which a recess into which a motor shaft is inserted is formed at one axial end of an input member, and a first-stage pinion of a reduction gear is integrally provided at the other axial end. .

  In general, the motor shaft (drive shaft) of the motor and the input member are generally coupled by a key coupling or a friction coupling using a slit, a wedge and a bolt.

  However, when used in a situation where an axial load is likely to be generated for some reason, for example, as a first stage pinion, axial component force (axial load) is generated with rotation, such as a helical pinion, bevel pinion, or hypoid pinion. When a pinion of this type is equipped, there is a problem that the axial load is transmitted to the motor shaft side via the input member, which may adversely affect the durability of the motor.

  In this case, it is necessary to take measures such as incorporating a bearing with a larger capacity. However, when using this type of input member, a general-purpose motor is often used as the motor. It is often difficult to change only the bearings. Therefore, as a result, the motor itself (whole) has to be changed to one rank or larger, leading to an increase in cost, an increase in weight, an increase in dimensions, and the like.

  In order to solve such a conventional problem, the applicant has improved the durability of the motor to be connected at a lower cost based on the knowledge obtained as a result of investigating the mechanism of the durability deterioration in detail. A connecting part structure that can be used is provided by Patent Document 2 (unknown).

JP 2002-243043 A Japanese Patent Application No. 2003-283051 (unknown)

  The connecting portion structure according to Patent Document 2 includes “a coupling member having an insertion hole into which a drive shaft is inserted and fixed” and “an input member on which a pinion or a roller is mounted or formed”. The ring member and the input member) are bolt-connected through a buffer mechanism.

  In this case, the bolt is incorporated in such a manner that a predetermined play is allowed with respect to the coupling member. This is because it is necessary to absorb a shift in the formation position of the bolt through hole on the coupling member side and the screw hole on the input member side. For this reason, it is necessary to tighten the bolt after the shaft center of the coupling member and the shaft center of the input member are matched with each other by some method.

  However, when a separate mechanism or member such as a “buffer mechanism” is interposed between the coupling member and the input member, a general method of aligning the axes by so-called inlay engagement between the two is used. It cannot be adopted. Further, when the vicinity of the connecting portion is disposed inside the cylindrical casing, it is not possible to perform adjustment by the technique of “matching the outer peripheral surfaces of two members formed to have the same diameter”. For this reason, it is extremely difficult to align the shaft centers, and for mass production, it is necessary to ensure both the alignment accuracy of the shaft centers and the ease of manufacturing.

  The present invention has been made in view of the above problems, and an object thereof is to enable easy and high-precision bolt connection in this type of connecting portion structure.

  The present invention provides a coupling member having an insertion port into which a drive shaft is inserted and fixed, an input member of a transmission on which a pinion or a roller is mounted or formed, and a bolt that penetrates the coupling member as the input member. The transmission and the drive shaft are connected by screwing into a screw hole formed on the end surface of the input member, and the end of the input member on the coupling member side is larger than the outer peripheral surface of the coupling member. A large-sized portion having an outer peripheral surface is formed, and at least a part of the outer peripheral surface of the coupling member and at least a part of the outer peripheral surface of the large-sized portion are centered between the coupling member and the input member, respectively. Therefore, the above-described problem is solved by using a processed surface that can be used as the first and second reference surfaces.

  Further, the present invention provides a transmission having such a connecting portion structure with a first inner peripheral surface engageable with the first reference surface and a second inner peripheral surface engageable with the second reference surface. A step of preparing a jig having a coaxial surface, and a state in which the second inner peripheral surface of the jig is connected to the second reference surface in a state where the coupling member is engaged with the first inner peripheral surface of the jig. And in this state, the bolt is screwed into a screw hole formed in the input member through the bolt through hole formed in the coupling member. It has been solved.

  According to the present invention, the input member is provided with a large portion having an outer peripheral surface larger than the outer peripheral surface of the coupling member at the end of the coupling member. As a result, a jig that can be engaged with both the outer peripheral surface (all or a part) of the coupling member and the outer peripheral surface (the whole or a part thereof) of the large-shaped portion is extended along the axial direction from the drive source side. Can be inserted. As a result, the outer peripheral surface of the coupling member and the outer peripheral surface of the large portion can be used as the first and second reference surfaces for centering the coupling member and the input member, respectively.

  Note that the “coupling member” and the “input member of the transmission” in the present invention do not necessarily have to be coupled with a buffer mechanism interposed therebetween, for example, both are directly coupled. It is also applicable to

  The coupling member can be bolt-coupled to the input member with the axis center aligned easily and accurately.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of a geared motor to which a connecting portion structure according to the present invention is applied.

  The geared motor GM is obtained by connecting and integrating the motor 10 and the speed reducer 20 via a connecting portion C. FIG. 2 is a side view of the connecting portion C as viewed from the motor 10 side.

  A motor shaft (drive shaft) 12 of the motor 10 is inserted into a motor shaft insertion hole 24 of a coupling plate (coupling member) 22 in the connecting portion C. In the connecting portion C, the coupling plate 22, the input member 26, and the buffer mechanism 28 are connected by bolts 30 (and 31). The motor shaft 12 and the coupling plate 22 are frictionally fastened by a clamp bolt 25.

  As shown in FIG. 3, the coupling plate 22 includes a motor shaft insertion hole 24 into which the motor shaft 12 is inserted and a bolt through hole 32 for allowing the bolt 30 to pass therethrough. The bolt through hole 32 has a larger inner diameter than the head of the bolt 30, and through holes 40 </ b> A and 40 </ b> C of the spring 40 of the buffer mechanism 28 described later are larger than the screw diameter of the bolt 30. Therefore, as a result, the bolt 30 is incorporated in a manner in which a predetermined play is allowed with respect to the coupling plate 22. That is, the relative position between the bolt 30 and the coupling plate 22 is not uniquely determined.

  The outer peripheral surface 22 </ b> A of the coupling plate 22 is a machined surface processed with high accuracy that can form the first reference surface Re <b> 1 for centering the coupling plate 22 and the input member 26. The outer diameter of the first reference plane Re1 is d1.

  The input member 26 of the coupling portion C has a large portion 34 having an outer peripheral surface 34A having an outer diameter d2 larger than the outer diameter d1 of the outer peripheral surface 22A of the coupling plate 22 at the end on the coupling plate 22 side. Prepare. The outer peripheral surface 34A of the large-shaped portion 34 is a processed surface processed with an accuracy capable of forming the second reference surface Re2 when the coupling plate 22 and the input member 26 are centered.

  The difference d2-d1 between the outer diameters d2 and d1 is secured to about 0.2 mm to 5.0 mm. This is to ensure that the worker can recognize the boundaries between the outer peripheral surfaces 22A and 34A (first and second reference surfaces Re1 and Re2) when the jig 80 described later is engaged with this portion. It is. If this is too small, the operator cannot recognize the boundary between the outer peripheral surfaces 22A and 34A when the jig 80 is inserted, and if this is too large, the first and second described later will be used in manufacturing the jig 80 itself. 2 It becomes difficult to ensure the coaxiality of the inner peripheral surfaces 84 and 86 with high accuracy.

  The axial length L of the outer peripheral surface 34A (second reference surface Re2) of the large portion 34 is secured to, for example, about 1 mm to 10 mm, preferably about 3 mm to 10 mm. If this axial length L is too short, axial alignment using the jig 80 described later will be inaccurate, and if it is too long, the jig 80 for the first and second reference planes Re1 and Re2 will be incorrect. Engagement / removal becomes difficult.

  In this embodiment, the outer peripheral surface 22A of the coupling plate 22 and the outer peripheral surface 34A of the large-shaped portion 34 of the input member 26 all constitute first and second reference surfaces Re1 and Re2, respectively. However, it is not always necessary to cover the entire surface, and only a part of it may have a structure constituting the first and second reference surfaces Re1 and Re2. The end face 34B of the large portion 34 functions as an end face for positioning in the axial direction of a jig 80 described later.

  A buffer mechanism 28 is interposed between the coupling plate 22 and the input member 26. The shock absorbing mechanism 28 is for absorbing axial torque (especially shocking torque) between the coupling plate 22 and the input member 26. As shown in FIG. It is configured. The spring 40 is a substantially rectangular thin metal plate, and four through holes 40A to 40D are formed in the vicinity of the apex thereof. The ring-shaped spacers 42 are arranged on the front and back of the positions corresponding to the bolt holes 40A to 40D. Note that the arrangement of the spacer 42 can be omitted by integrally forming a projection (not shown) having a size corresponding to the spacer 42 on the coupling 22 or the input member 26 itself by casting or the like.

  As shown in FIG. 3A, among the four through-holes 40 </ b> A to 40 </ b> D, a pair facing each other (in the illustrated example, 40 </ b> A and 40 </ b> C hatched) connects the leaf spring 40 via the bolt 30 to the input member 26. It is a through-hole for fixing to. As described above, the inner diameters of these through holes 40 </ b> A and 40 </ b> C are larger than the screw diameter of the bolt 30. Further, another pair (40B and 40D in the illustrated example) facing each other is a through hole for fixing the leaf spring 40 to the coupling plate 22 side via the bolt 31.

  Therefore, as shown in FIG. 3C, the end face of the input member 26 (the large portion 34) has a screw hole 36 for screwing the bolt 30 from the motor 10 side, and the large portion 34 side. Two counterbores (recesses) 38 for receiving the heads of the bolts 31 are formed. As shown in FIG. 3 (B), the bolt through hole 32 for passing the bolt 30 from the motor 10 side and the bolt 31 from the large portion 34 side are screwed into the coupling plate 22. Two screw holes 33 are formed. The bolt 30 has a hexagonal slot 30 </ b> A formed on the head thereof for screwing with a tool (hexagonal wrench: described later).

  The thickness and material of the leaf spring 40 are such that when the axial component force (axial load) expected to occur during operation is applied to the leaf spring 40, the amount of axial deformation supports the input member 26. The bearing 48 (see FIG. 1) is selected so as to be larger than the axial play.

  A specific configuration of the speed reducer 20 will be briefly described. The speed reducer 20 in this embodiment includes a helical pinion (sun gear) 50 press-fitted into an input member 26, a planetary gear 52 that meshes with the helical pinion 50, and a ring gear 54, and a simple planetary gear mechanism that extracts an output from a carrier 56. The front reduction gear 58, a sun gear 60 that is spline-engaged with the carrier 56, a planetary gear 62 that meshes with the sun gear 60, and a ring gear 64, and outputs from an output shaft 68 that is integrated with the carrier 66. And a rear stage reduction unit 70 of the simple planetary gear mechanism. A plate 72 is rotatably supported by a bearing 73 on the opposite output shaft side of the planetary gear 62 of the post-stage reduction unit 70, and the carrier 66 is integrated with the plate 72 via a bolt 79.

  A casing 74 of the speed reducer 20 includes a flange-like coupling case 74A that accommodates the coupling plate 22, an input side case 74B that accommodates the input member 26, a center case 74C that is integrated with the ring gear 54 of the front speed reducing portion 58, And it consists of four pieces of output side case 74D integrated with the ring gear 64 of the rear stage reduction part 70, and is connected with volt | bolts 76, 78, etc., respectively.

  Here, a jig 80 used for assembling the connecting portion C of the geared motor GM will be described with reference to FIG. Note that the jig 80 of FIG. 4 is shown in an aspect in which the upper half is an end face and the lower half is a cross section.

  The jig 80 includes a through hole 82 having a step. A first inner peripheral surface 84 that can be engaged with the first reference surface Re1 is formed in the center in the axial direction of the through hole 82, and the second reference surface Re2 is further provided on the axial front end side (left end side in the figure). A second inner peripheral surface 86 that can be engaged with the first inner peripheral surface 84 is formed coaxially with the first inner peripheral surface 84. The first inner peripheral surface 84 and the second inner peripheral surface 86 are respectively formed with groove portions 84A and 86A that allow the O-rings 85 and 87 to be interposed between the first and second reference surfaces Re1 and Re2. ing.

  The rear end side (right side in the figure) of the jig 80 is formed thick, and a tool through hole 90 concentric with the bolt through hole 32 of the coupling plate 22 is formed. The tool through-hole 90 is formed with a screw portion 88 into which the tool support nut 92 can be screwed, and an insertion hole 99 into which a tool (hexagonal wrench) 98 can be inserted is formed inside the tool support nut 92. . Further, a step 94 is formed at the tip of the tool through hole 90 by reducing the inner diameter thereof, and a rubber ring 96 can be engaged therewith.

  Next, a method of connecting the coupling plate 22 and the input member 26 using the jig 80 will be described in detail with reference to FIG. In addition, in FIG. 5, the circumferential direction position of each member is suitably changed and depicted for convenience.

  First, the coupling plate 22 and the leaf spring 40 of the buffer mechanism 28 are coupled by the bolt 31 via the spacer 42. Next, the first reference surface Re1 of the coupling plate 22 (with the leaf spring 40) is engaged with the first inner peripheral surface 84 of the jig 80 in a state where the bolt 30 is incorporated in the bolt through hole 32 of the coupling plate 22. Combine. If the front end of the bolt 30 is inserted into the spacer 42 and the through holes 40A and 40C of the leaf spring 40 in advance, the subsequent screwing becomes easy.

  In this state, the second inner peripheral surface 86 of the jig 80 is engaged with the second reference surface Re2 which is the outer peripheral surface 34A of the large portion 34 of the input member 26. At this time, the end face 34B of the large portion 34 of the input member 26 functions as an end face for positioning the jig 80 in the axial direction. In addition, O-rings 85 and 87 are attached in advance to the groove portions 84A and 86A of the jig 80. Due to the presence of the O-rings 85 and 87, the inner diameters of the first and second inner peripheral surfaces 84 and 86 of the jig 80 are set slightly larger than the outer diameters d1 and d2 of the first and second reference surfaces. The first and second inner peripheral surfaces 84 and 86 can be reliably engaged with the first and second reference surfaces without being shaken while ensuring ease of insertion.

  In this embodiment, the outer peripheral surface 34A having an outer diameter d2 larger than the outer diameter d1 of the outer peripheral surface 22A (first reference surface Re1) of the coupling plate 22 at the end of the input member 26 on the coupling plate 22 side. Since the large-sized portion 34 having the (second reference surface Re2) is formed, the first and second engagements with both the first and second reference surfaces Re1 and Re2 are thus performed. The jig 80 having the inner peripheral surfaces 84 and 86 can be inserted along the axial direction from the motor 10 side. As a result, the coupling plate 22 and the input member 26 (the large portion 34 thereof) are coaxially formed by the jig 80, and the eccentric distance between them is within the allowable range A or less (in this embodiment, 0.02 mm or less). .

  On the other hand, the tool support nut 92 is screwed into the threaded portion 88 of the tool through hole 90 of the jig 80 with the rubber ring 96 attached to the stepped portion 94. By inserting the tool 98 through the insertion hole 99 of the tool support nut 92, the bolt 30 is screwed into the screw hole 36 of the large portion 34 of the input member 26 through the bolt through hole 32 of the coupling plate 22. be able to.

  At this time, in particular, the tool support nut 92 is screwed into the threaded portion 88 to deform the rubber ring 96, whereby the tool 98 can be favorably supported by the tool support nut 92 and the deformed rubber ring 96. Therefore, even if there is a long distance between the operating point 98A of the tool 98 and the bolt 30, the bolt 30 can be easily and reliably screwed.

  In general, when a buffer mechanism or the like is interposed between the coupling member and the input member as in the above embodiment, the coupling member and the input member are aligned with each other due to the presence of the buffer mechanism or the like. Cannot be performed by “inlay fitting” that is generally used. However, in this embodiment, by using the jig 80, the coupling plate 22 and the input member 26 can be easily coaxially connected.

  When the screwing of the bolt 30 is completed, the jig 80 is removed, the motor shaft 12 is inserted into the insertion hole 24 of the coupling plate 22, and the coupling plate 22 and the motor shaft 12 are frictionally fastened by the bolt 25.

  In the above-described embodiment, the buffer mechanism 28 is interposed between the coupling member (coupling plate 22) and the input member 26 (large portion 34 thereof). The intervention of the mechanism 28 is not always necessary, and can be applied even when the coupling member and the input member are directly connected. Further, the present invention can also be applied when any member or mechanism other than the buffer mechanism is interposed.

  Furthermore, the configuration of the speed reducer is not particularly limited to the above configuration. Further, the connection between the drive shaft insertion hole of the coupling member and the drive shaft is not limited to the frictional fastening as described above, and may be connected by a key, for example.

  A screw hole in which a coupling member having an insertion port into which a drive shaft is inserted and fixed and an input member on which a pinion or a roller is mounted or formed are formed on the end surface of the input member with a bolt penetrating the coupling member The present invention can be applied to a connecting portion between a transmission and a drive shaft which are connected by being screwed into the shaft.

The longitudinal cross-sectional view of the geared motor to which the connection part structure which concerns on this invention was applied The side view which looked at the connection part of the motor shaft in the said geared motor and the input member of a reduction gear from the motor side The structure around the buffer mechanism of the connecting portion is shown, (B) is a front view thereof, (A) is an AA sectional view of (B), (C) is a CC sectional view of (B). Exploded view showing jigs etc. used for assembly of the connecting part Sectional drawing which showed a mode that a connection part was assembled using the said jig | tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Motor 12 ... Motor shaft 22 ... Coupling plate (coupling member)
22A ... outer peripheral surface (first reference surface: Re1)
24 ... Motor insertion hole 26 ... Input member 30, 31 ... Bolt 32 ... Bolt through hole 33, 36 ... Screw hole 34 ... Large portion 34A ... Outer peripheral surface (second reference surface: Re2)
40 ... leaf spring 42 ... spacer 88 ... threaded portion 92 ... tool support nut 98 ... tool

Claims (4)

A coupling member having an insertion port into which a drive shaft is inserted and fixed, and an input member of a transmission on which a pinion or a roller is mounted or formed, and a bolt penetrating the coupling member are formed on an end surface of the input member A connecting portion structure of a transmission and a drive shaft that are connected by screwing into a screw hole,
On the coupling member side of the input member, a large portion having an outer peripheral surface larger than the outer peripheral surface of the coupling member is formed, and
At least a part of the outer peripheral surface of the coupling member and at least a part of the outer peripheral surface of the large-sized portion may be used as first and second reference surfaces for centering the coupling member and the input member, respectively. The structure of the connecting part between the transmission and the drive shaft, characterized by having a machined surface. In claim 1,
The coupling member and the input member are connected to each other by the bolt via a shock absorbing mechanism that can extend and contract in the axial direction. For the transmission having the connecting portion structure according to claim 1,
Preparing a jig having a first inner peripheral surface engageable with the first reference surface and a second inner peripheral surface engageable with the second reference surface coaxially;
A step of engaging the second inner peripheral surface of the jig with the second reference surface in a state where the first reference surface of the coupling member is engaged with the first inner peripheral surface of the jig;
Screwing the bolt into a screw hole formed in the input member through a bolt through hole formed in the coupling member in this state, and a transmission using a jig and a drive shaft Concatenation method. In claim 3,
The jig has a tool through hole concentric with the bolt through hole of the coupling member;
A method of connecting a transmission and a drive shaft using a jig, wherein the bolt is screwed into a screw hole formed in the input member through the tool through hole and the bolt through hole.

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